AMD vs Intel and Nvidia vs ATI.

It is all 6 of one half a dozen of the other.

You get what you pay for. Although they say no one ever got fired for ordering Intel

Generally you get more bang for you buck with AMD (talking about their proper CPUs not the celeron equivalents). And it is a toss up between ATI and Nvidia I have had very good experience with both manufacturers.

In the past I tried to "future proof" our purchases but found through experience that by the time you wish to upgrade so much had changed that it was better to start a fresh.

Also from experience if you buy the best and most expensive then expect problems. If you buy hardware that has been out for a wee while you tend to get stable equipment.

At the moment my choice would be a 64 bit AMD with decent mobo. And as for a video card either one of the newer ATI cards (x1800 or a nvidia 7800). 1 gig ram minimum.